diff options
| -rw-r--r-- | llvm/test/Transforms/InstSimplify/result-of-add-of-negative-is-non-zero-and-no-underflow.ll | 24 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstSimplify/result-of-usub-is-non-zero-and-no-overflow.ll | 44 |
2 files changed, 68 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstSimplify/result-of-add-of-negative-is-non-zero-and-no-underflow.ll b/llvm/test/Transforms/InstSimplify/result-of-add-of-negative-is-non-zero-and-no-underflow.ll index 58a56c4d7ba..9521a71bd70 100644 --- a/llvm/test/Transforms/InstSimplify/result-of-add-of-negative-is-non-zero-and-no-underflow.ll +++ b/llvm/test/Transforms/InstSimplify/result-of-add-of-negative-is-non-zero-and-no-underflow.ll @@ -99,3 +99,27 @@ define i1 @t4_commutative(i8 %base, i8 %offset) { %r = and i1 %not_null, %no_underflow ret i1 %r } + +; We only need to know that any of the 'add' operands is non-zero, +; not necessarily the one used in the comparison. +define i1 @t5(i8 %base, i8 %offset) { +; CHECK-LABEL: @t5( +; CHECK-NEXT: [[CMP:%.*]] = icmp slt i8 [[OFFSET:%.*]], 0 +; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) +; CHECK-NEXT: [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET]] +; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) +; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 +; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[BASE]] +; CHECK-NEXT: [[R:%.*]] = or i1 [[NOT_NULL]], [[NO_UNDERFLOW]] +; CHECK-NEXT: ret i1 [[R]] +; + %cmp = icmp slt i8 %offset, 0 + call void @llvm.assume(i1 %cmp) + + %adjusted = add i8 %base, %offset + call void @use8(i8 %adjusted) + %not_null = icmp ne i8 %adjusted, 0 + %no_underflow = icmp ult i8 %adjusted, %base + %r = or i1 %not_null, %no_underflow + ret i1 %r +} diff --git a/llvm/test/Transforms/InstSimplify/result-of-usub-is-non-zero-and-no-overflow.ll b/llvm/test/Transforms/InstSimplify/result-of-usub-is-non-zero-and-no-overflow.ll index 66ff797c252..fcc48310951 100644 --- a/llvm/test/Transforms/InstSimplify/result-of-usub-is-non-zero-and-no-overflow.ll +++ b/llvm/test/Transforms/InstSimplify/result-of-usub-is-non-zero-and-no-overflow.ll @@ -138,3 +138,47 @@ define i1 @t2_commutativity(i8 %base, i8 %offset) { %r = and i1 %null, %underflow ret i1 %r } + +; Overflow OR not zero => always true +define i1 @t3(i8 %base, i8 %offset) { +; CHECK-LABEL: @t3( +; CHECK-NEXT: [[ADJUSTED:%.*]] = sub i8 [[BASE:%.*]], [[OFFSET:%.*]] +; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) +; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ule i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: call void @use1(i1 [[NO_UNDERFLOW]]) +; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0 +; CHECK-NEXT: call void @use1(i1 [[NOT_NULL]]) +; CHECK-NEXT: [[R:%.*]] = or i1 [[NOT_NULL]], [[NO_UNDERFLOW]] +; CHECK-NEXT: ret i1 [[R]] +; + %adjusted = sub i8 %base, %offset + call void @use8(i8 %adjusted) + %no_underflow = icmp ule i8 %base, %offset + call void @use1(i1 %no_underflow) + %not_null = icmp ne i8 %adjusted, 0 + call void @use1(i1 %not_null) + %r = or i1 %not_null, %no_underflow + ret i1 %r +} + +; No overflow and zero => always false +define i1 @t4(i8 %base, i8 %offset) { +; CHECK-LABEL: @t4( +; CHECK-NEXT: [[ADJUSTED:%.*]] = sub i8 [[BASE:%.*]], [[OFFSET:%.*]] +; CHECK-NEXT: call void @use8(i8 [[ADJUSTED]]) +; CHECK-NEXT: [[NO_UNDERFLOW:%.*]] = icmp ugt i8 [[BASE]], [[OFFSET]] +; CHECK-NEXT: call void @use1(i1 [[NO_UNDERFLOW]]) +; CHECK-NEXT: [[NOT_NULL:%.*]] = icmp eq i8 [[ADJUSTED]], 0 +; CHECK-NEXT: call void @use1(i1 [[NOT_NULL]]) +; CHECK-NEXT: [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]] +; CHECK-NEXT: ret i1 [[R]] +; + %adjusted = sub i8 %base, %offset + call void @use8(i8 %adjusted) + %no_underflow = icmp ugt i8 %base, %offset + call void @use1(i1 %no_underflow) + %not_null = icmp eq i8 %adjusted, 0 + call void @use1(i1 %not_null) + %r = and i1 %not_null, %no_underflow + ret i1 %r +} |
